Waste lubricating oil from automotive and industrial sources is an environmental problem. Waste lubricating oil has substantially no economic value. It is collected by service stations as a public service and transferred by bulk carrier to reprocessers who centrifuge and filter the oil and resell it as reprocessed lubricating oil, or who centrifuge and filter the oil and spray it into burners and industrial processors.
In both cases, remaining solids and sludge are an environmental hazard.
A need exists for a process to convert used lubricating oil into more economic products. A need exists to dispose of waste oil and sludge in environmentally safe processes.